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Aeolian processes play an essential role not only in the dynamics of beaches and deserts on the Earth, but also contribute to surface landforms on several bodies in our solar system. 11.2 Planetary Atmospheres There are at least four bodies in our solar system that have sufficient enough atmosphere to sustain winds that can transport sediment: Mars, Titan, Venus, and Earth. These atmospheres interact with geological processes and influence the morphology and composition of surfaces (Grotzinger et al. 2013). 11.2.1 Mars Landforms and geochemical signatures suggest that the atmosphere of Mars was significantly thicker in its past, even as Mars today has the thinnest atmosphere of all the bodies that contain confirmed aeolian features. On Mars. the orbital parameters of

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Abstract. We have generated sub-millimetre resolution DEMs of weathered rock surfaces using SfM photogrammetry techniques. We apply a close-range Structure from Motion (SfM) photogrammetry-based method in the field and use it to generate high-resolution topographic data for weathered boulders and bedrock. The method was pilot tested on extensively weathered Triassic Moenkopi Sandstone outcrops near Meteor Crater in Arizona. Images were taken in the field using a consumer grade DSLR camera and were processed in commercially available software Agisoft Photoscan to build dense point cloud. Dense point clouds were registered to a local 3D coordinate system (x, y, z) which was developed using a specially designed triangle coded control target and then exported as Digital Elevation Models (DEMs). The accuracy of the DEMs was validated under controlled experimental conditions. A number of checkpoints were used to calculate errors. We also evaluated the effects of image and camera parameters on the accuracy of our DEMs. We report a horizontal error of 0.5 mm and vertical error of 0.3 mm in our experiments. Our approach provides a low-cost method, for obtaining very high-resolution topographic data on weathered rock surfaces (area

The local redistribution of granular material by sublimation of the southern seasonal CO 2 ice deposit is one of the most active surface shaping processes on Mars today. This unique geomorphic mechanism has been linked to the dendritic, branching, 'spider'-like araneiform terrain and associated fans and spots-features which are native to Mars and have no Earth analogues. However, there is a paucity of empirical data to test the validity of this genetic hypothesis. Additionally, it is unclear whether the organised radial patterns of araneiforms require a singular or multiple seasonal events to form. Here we present the results of a suite of laboratory experiments undertaken to investigate if the interaction between a sublimating CO 2 ice overburden with central vents and a porous, mobile regolith will mobilise grains from beneath the ice in the form of a plume to generate araneiform patterns. We investigate the physical constraints on the level of branching of these features and the area that they cover. We provide the first observations of plume activity via CO 2 sublimation and conse-1